Primality proof for n = 9311:
Take b = 2.
b^(n-1) mod n = 1.
19 is prime.
b^((n-1)/19)-1 mod n = 4238, which is a unit, inverse 8720.
7 is prime.
b^((n-1)/7)-1 mod n = 763, which is a unit, inverse 8530.
(7^2 * 19) divides n-1.
(7^2 * 19)^2 > n.
n is prime by Pocklington's theorem.